Ref: DIN 8140These diamond shaped hardened stainless steel thread inserts are typically used to repair stripped female threads. Since the resulting thread is generally stronger than the original thread, these helical inserts are often used in new production to reinforce female threads in high-stress applications. The insert lengths shown are "installed lengths" and they generally follow the formula of 1, 1.5, 2, 2.5 & 3 times the nominal thread diameter. Note that the tangs on the inserts must be removed after insallation.